Netgear WC7520 - ProSafe 20-AP Wireless Controller Reference Manual
Managing Stacking and Redundancy
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ProSafe 20-AP Wireless Controller WC7520
has a redundancy relationship with a primary controller. You need a unique VRRP ID for each
relationship.
relationship.
Each controller in the redundancy group has a unique controller IP address and a unique
local IP address. Local addresses remain constant so a controller can always be identified
before and after a failover. If the primary controller fails or is disconnected from the network,
an automatic failover to the redundant controller occurs. The redundant controller then takes
ownership of the controller IP address of the primary controller and takes over all functions of
the primary controller.
local IP address. Local addresses remain constant so a controller can always be identified
before and after a failover. If the primary controller fails or is disconnected from the network,
an automatic failover to the redundant controller occurs. The redundant controller then takes
ownership of the controller IP address of the primary controller and takes over all functions of
the primary controller.
After a failover has occurred, there is no longer any redundancy available for the other
primary controllers in the redundancy group.
primary controllers in the redundancy group.
When the primary controller that went down and for which the redundant controller took over
comes back up and is stable, a switchback occurs automatically, in which case ownership of
the controller IP address is returned to the primary controller that came back up. The
redundant controller reassumes its passive position, and redundancy is once again available
for all primary controllers in the redundancy group.
comes back up and is stable, a switchback occurs automatically, in which case ownership of
the controller IP address is returned to the primary controller that came back up. The
redundant controller reassumes its passive position, and redundancy is once again available
for all primary controllers in the redundancy group.
Note:
When a redundancy failover occurs, wireless clients might
experience a service interruption of a few seconds.
Requirements and Restrictions for N:1 Redundancy
These are the requirements and restrictions for N:1 redundancy to function correctly:
•
All controllers in a redundancy group need to be in the same management VLAN and IP
subnet.
•
The primary controllers need to be stacked.
•
If three or four controllers are in the same redundancy group, you need to configure one
controller as the redundant controller and all other controllers as primary controllers.
•
All controllers in the redundancy group need to run the same firmware version. If the
firmware versions do not match, redundancy does not work.
•
The licenses on the redundant controller need to match those on the primary controller
that has the largest number of licenses. For example, in a redundancy group with two
primary controllers, if one primary controller has a license for 20 access points and the
other primary controller has a license for 50 access point, the redundant controller needs
to have a license for 50 access point. If the licenses do not match, redundancy does not
work.
primary controllers, if one primary controller has a license for 20 access points and the
other primary controller has a license for 50 access point, the redundant controller needs
to have a license for 50 access point. If the licenses do not match, redundancy does not
work.
•
For the relationship of each primary controller with the redundant controller, you need to
configure a unique VRRP ID, also in relation to any other VRRP IDs that might be used
for other purposes in the network. You also need to configure a unique local controller IP
address for each controller in the redundancy group.
for other purposes in the network. You also need to configure a unique local controller IP
address for each controller in the redundancy group.